Răspuns :
A+b+c=27
A=3xb
C=b+7
A,b,c=?
B |-----|}
A|--------|----------|---------|}
C|--------| -------+7 }
27-7=20
20:5=4
4x3=12
4+7=11
V: 4+12+11=27
a+b+c=27
a=3b
c=b+7
3b+b+b+7=27
5b=27-7
5b=20
b=20:5=4
a=3b=3x4=12
c=b+7=4+7=11
12+4+11=27(verificare
a+b+c=98
b=2a
c=a+18
a+2a+a+18=98
4a=98-18
4a=80
a=80:4=20
b=2a=2x20=40
c=a+18=20+18=38
20+40+38=98(verificare)
a+b+c=108
b=a+19
c=a+20
a+a+19+a+20=108
3a=108-39
3a=69
a=69:3=23
b=a+19=23+19=42
c=a+20=23+20=43
23+42+43=108
a=3b
c=b+7
3b+b+b+7=27
5b=27-7
5b=20
b=20:5=4
a=3b=3x4=12
c=b+7=4+7=11
12+4+11=27(verificare
a+b+c=98
b=2a
c=a+18
a+2a+a+18=98
4a=98-18
4a=80
a=80:4=20
b=2a=2x20=40
c=a+18=20+18=38
20+40+38=98(verificare)
a+b+c=108
b=a+19
c=a+20
a+a+19+a+20=108
3a=108-39
3a=69
a=69:3=23
b=a+19=23+19=42
c=a+20=23+20=43
23+42+43=108